Lower rad hose question

Hi ,
Got a 75,000 225 slant in a 68 rag Dart GT.
Replaced all rad hoses this year and all was good.
Car has 3:21 gears and 26" tire so 3200 rpm keeps up on the highway.
I have found the car gets hotter the more rpm. 160 deg thermostat and new rad cap. The new lower rad hose came without spring so I installed.
After a 100 miles found the hose collapsing at higher rpm.
Installed new spring in lower hose and now car is running even hotter (190-200).
Should I install a lower rad hose restrictor (I know the thermostat is some what of a restrictor).
Just thinking that the collapsing hose allowed the water to have a larger "delta T" at the rad.
Also any thoughts on slowing down (larger pulley) the water pump to assist in the cooling at the higher rpm.



Thanks in advance.